26 BULLETIN 301, U. S. DEPARTMEXT OF AGRICULTURE. 
fur greatly improved. Within 16 years from the time the two pioneer 
fox-breeders built their ranch, they were sending to market the finest 
fox pelts in the world. 
The tendency of wild silvers to produce red progeny is accounted 
for by the fact that owing to their scarcity probably only one in a 
hundred can have a silver mate; perhaps three in a hundred may 
mate with cross foxes, which are merely hybrids, or descendants from 
hybrids, between silvers and reds ; and the remaining ninety-six must 
mate with reds. In any event, although gome of the cubs may be 
silver, all of them will inherit from their red ancestors a tendency to 
throw red. As has already been pointed out, however, this tendency 
very soon disappears under the influence of careful breeding. Gen- 
erally speaking, pure strains of silver foxes breed true. So also do 
pure strains of red. When a red and silver are mated together, the 
color of the progeny can not be foretold. The cubs may be red with 
black throats, or they may be crosses, or a mixture of the two. One 
or more may be silver, but this is unusual. Random breeding from 
silvers and crosses of unknown pedigree is equally uncertain, as is 
shown by the following results: 
A silver mated with a red produced two crosses, which when mated 
together produced one red and four silvers. A silver and a cross 
produced three silvers and two reds. A cross and a red produced 
two crosses and two reds. A cross and a cross produced two silvers, 
two crosses, and one red. Another pair of crosses produced nine 
crosses. A red of silver-cross parentage mated with a red of silver 
parentage produced one silver and two crosses. A silver and a red 
produced in two successive years thirteen silvers. A pair of reds 
from the same litter as two silvers produced three silvers, one cross, 
and two reds. A pair of silvers produced one silver and five reds, 
two of which, when mated together, produced three silvers and one 
red the first year and two silvers the next year. Another pair of 
silvers produced four crosses; while a silver and a cross produced a 
litter of all silvers. 
These results indicate the uncertainty of breeding at random, but 
they show also that if a fox of any color whatever has in his veins 
silver blood, the silver can be made to appear in succeeding genera- 
tions by selective breeding. This fact is most important. Suppose 
a breeder has a strain of silvers lacking in size, or fecundity, or in 
some other desirable particular. He can introduce specimens having 
the desired qualities without having to consider color. A red fox 
can be used if one of better color is not available. In the course of 
three or four generations the silver can be fully reinstated. Among 
the features to be considered besides color are size, fineness of fur, 
fecundity, docility, and hardiness. Fecundity appears to be a 
